and in the Serum of the Blood. 125 



times larger*. But! carry the point still further ; fori 

 go the length of believing, that many experiments of re- 

 search may be wonderfully facilitated t)y analysing upon a 

 small scale — that a great deal of convenience, of ceconomy, 

 and son)etimes even of accuracy, n)ay thus be gained ; and 

 that, in some instances, we even acquire new powers of in- 

 quiry by operating upon small quantities j". 



Thus, were it not for the assistance of minute microscopic 

 observation, a great number of important facts which 

 have enriched chemistry within the last twenty years, would 

 in all probability have remained undiscovered ; and this 

 country might not have obtained that first rank in philoso- 

 phical chemistry, to which it has but lately been raised, and 

 uhich it had long held in other departments of science. 



Is it necessary that I should specify particular instances? 

 Can any philosopher, attentive to the progress of analytical 

 chemistry, overlook so many discoveries m which neither 

 furnace, nor foro;e, nor subterraneous laboratories, have 

 been concerned — in which a watch glass, a blow-pipe, and 

 a few drcjps of chenjieal re-agents, have been all the in- 

 struments required ? Were not, for instance, the analyses of 

 the Iceland springs by Dr. Black (the same eminent phi- 

 losopher to whom Dr. Pearson appeals as an authority 

 against microscopic observations) performed upon quanti- 

 ties of saline matter of astonishing minuteness ? — Surely Dr. 

 Pearst)n cannot have forgotten that it was by the accurate 

 examination of only a few grains of matter, that the na- 

 ture of no less than five kinds of urinary calculi has been 

 ascertained, and their discrimination rendered easy and cer- 

 tain — <hat the nature of diamond has been established — that 

 no less than four new metals have been discovered in the 

 crude ore of platina — that the siniilarity between all the 



* Thus. I have no hesitation in maintaining that, unless it be proved that 

 nltrat of potash may crystalhze in rhombs, my conclusions respecting' tlie 

 particular point in ijuestion, would stand upon that evidence ahnie; or that 

 unle^s it be sliown that carhonat of potash may crystallize in cubes, my 

 inforence respectinjj the presence of inuriat ot potash stands uucontro- 

 verted. 



With regard to my attempt at expressing centesimal parts of grains, 

 which is, with some apparent reason, noticed as an instance of singular pre- 

 tension to accuracy, I beg to observe, that I have never actually attempted 

 to weigh smaller (juanliiies than decmial parts c.f grains; and wlienever 

 smaller fraction^, have been expressed, they have arisen from a conversion 

 of those numbers to some general standard. 



f 1 would also observe, whiUt upon this subject, that there is a degree of 

 neatness gained by reducing the scale of operations, which is ofteu incom- 

 patible with processes conducted in the large way : thtu, I have never found 

 It necctsary, in analysing, tc> introduce amongst the enumeration of contents 

 " a lutlc dirt," as i>ome old-school cbcansis have bct:u in the habit of doing. 



meteoric 



